You could read 100 books and still not know enough because certain things must be learned through trial and error.

There are typically a lot more variations in unit characteristics with 2-4 units properties than with larger apartment houses, etc. 

Some I guess will never get tired of dealing with tenants or property managers (I've had to manage my recent trial of one this past year, they sucked).

@Ross HamiltonAny "revolutionary new real-estate investment service" that expects to bilk me out of thou$ands of dollars, up front, without offering a limited free-trial sends goose-alarms down my back and will get my spidey-sense tingling faster than a hound-dog licks its rear.  

Here is a list of items that can search on:I've got a link to a free trial in my signature line. 

There are lots of resources out there to help with SEO if you do a search for Vacation Rental SEO or some variation of that.

When deciding between investing out of state vs home hacking in Oakland, keep the following in mind.Oakland House Hacking:Proximity: Living in Oakland while house hacking enables you to maintain a close proximity to San Francisco, which might prove advantageous for property management and maintaining connections with the local market.Possibility of Appreciation: Property values in the Bay Area have increased historically, which is good for accumulating equity over time.Local market dynamics, tenant preferences, and potential obstacles might be simpler to comprehend when one is in a familiar location.Demand for Rentals: Oakland has a robust rental market, and you can discover good demand for rental units if you pick the appropriate property and location.Creating Local Connections: If you live in the Bay Area, house hacking can assist you in making local contacts with property managers, real estate agents, and other investors.Investing Out of State:Investing outside of your state may be more affordable and enable you to use the same funds to buy more than one property.A few out-of-state markets can have more favorable cash flow prospects in contrast to the pricey Bay Area market.Geographic diversity, which can help reduce risks related to market-specific variations, is made possible by investing in a variety of markets.Hiring a local property management business, which offers a more hands-off approach to property management, is often necessary for out-of-state investments.Remember, both options have their advantages and challenges.

The property can not be refinanced for greater than the amount purchased for at least 6 monthsAre we using the same definition or do you have another one or some other variation?

1) Air-DNA; either premium version or free trial.2) An Excel spreadsheet that contains all the raw data from Airbnb for all the listings within a city (just like if someone collected the data manually for each listing).3) Other software/app.Appreciate your thoughts on this!

All these contacts and especially the sub contractor base are hard earned relationships through trial and error.